Hey there

Gate exam is graduate aptitude test in engineering. It was actually made for candidates who wanted higher studies in engineering but later on due to addition of PSUs and others it has become so popular. For gate I'll suggest you to just finish your syllabus of gate by any means may it by lectures or by coaching then you'll need to take your test series. You may purchase made easy or ace academy study material if needed but it depends on you. Generally one should start preparing for gate ideally in 3rd year as in final year you'll have much more pressure.

Check about gate

https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/exams/gate&ved=2ahUKEwi_lIDa7_vkAhXGZCsKHT_wA74QFjABegQIBRAB&usg=AOvVaw1b5AFUdR7TQ-b-mDgKoEox

Good luck